Insecticidal material of alkaloid pectates



Patented July 9, 1940 UNITED STATES PATENT o FIcE INSECTICIDAL MATERIALOF'ALKALOID PECTATES Willard E. Baler, Ontario, Calif., assignor toCali-' fornia Fruit Growers- Exchange, Los Angeles, Calif., acorporation of California No Drawing. Application May 2, 1940,

Serial No. 333,031 v 10 Claims. (01. 260-21(l) This invention relates,in general, to a new insecticidal material, and, in particular, topreparations of a pectate and a volatile poisonous alkaloid which arecomparatively free from the objectionable odors usually associated withsuch alkaloidal insecticides when prepared in combination with materialsof vegetable origin.

This application is a .continuation in part of co-pending applicationSerial No. 217,581,-filed July 5, 1938.

Many difierent kinds and types of materials and compositions have beenproposed for use as insecticides on growing plants. Much difiiculty,however, has been experienced with many of these compositions, sincethose that are the most effective as insecticides often damage the plantgrowth to which the compositions are applied, if extreme care is notexercised in their use. Oil spraying of citrus trees and fruit vmay betaken as a case in point, since, if the sprays are not properly mixedand are not applied in carefully controlled concentration, they may havean injurious effect on the fruit and foliage of the; plant.

It has been suggested that nicotine in combination with variousmaterials of vegetable origin, as, for example, nicotine tannate,nicotine humate, and nicotine peat, could be used to exterminate thevarious chewing insects with which agricultural crops are infested.These substances, while useful in part, have a disadvantage of acharacteristically disagreeable and undesirable odor of nicotine. Thisundesirable odor is due to a lack of stability of these insecticides andrepresents loss of nicotine by volatilization with a consequent decreasein the efiiciency of the compound for insecticidal purposes. Thisfeature has prevented their ready acceptance and use as commercialinsecticides. However, the fact that substances of this class leaveresidues which are readily removable is much in their favor and for thisreason I have considered it worthwhile to devote my time to thepreparationof a compound of this type which would be freefrom theobjectionable odors and be comparatively stable. 1 The present inventionis based upon the discovery that it is possible to produce an alkaloidalinsecticide comprising the combination of vvolatile poisonous alkaloidsand a material of plant origin which is practically freefrom anyoffensive or objectionable odor and has a high stability. This inventionis further based upon the discovery that it is possible to produceinsecticides of this type which have a relatively high order ofeffectiveness in the extermination of chewing insects;

The invention is still further. characterized by the factthat thesealkaloidal insecticides leave residues which are, readily removable andfurther are easily available.

The substances which I find suitable for use *5 as such insecticides arecompounds of pecticsubstances and nicotine or co'niine or other volatilepoisonous alkaloids, which may be referred to as pectates of nicotineandconiine, etc.

Accordingly, the principal object of this invention is to disclosemethods and means of pro ducing an insecticide characterized by itsbeing practically free from any undesirable or offensive odor. Y

' A still further object of this invention is to disclose methods andmeans of producing an insecticide being characterized by its relativelygreat stability. I

Another object of this invention is to disclose methods and means ofproducing an insecticide characterized by its high toxicity effect onphytophagous insects.

A further object of this invention is to disclose methods and means ofproducing an insecticide of an adhesive nature, characterized byitsability to bind itself to the plant being treated.

Another and further object of this invention is to disclose methods andmeans of producing an insecticide which is readily digested by chewinginsects. Y

A further object of this invention is to disclose methods and means ofproducing an insecticide characterized by the fact that it isnon-injurious to the plant being treated.

A further object of this invention is to disclose methods and means ofproducing'an insecticide comprising pectates of volatile poisonousalkaloids.

' A still further object of this invention is'to disclose methodsandmeans of producing an insecticide comprising the pectates of nicotineand coniine.

Other objects, uses, advantages, and adaptations of this invention willbe apparent from an illustration of the invention hereinafter described.

The materials preferably used in accordance with this invention arepectic acid and nicotine alkaloid or coniine alkaloid, or other volatilepoisonous alkaloids.

Pectic acid from any suitable source may be employed. The pectic acidprepared in accordance with the disclosures in U. S. Patent No.2,132,065, issued October 4, 1938, and corresponding British Patent No.472,974, of October 1, 1937, has been found suitable.

Peotic acid may also be suitably prepared as follows:

To 5,400 liters of pectin liquor, extracted from lemon pulp by means ofa hot 0.5% solution of sulphur dioxide and having a pectinconcentration, after evaporation of the $02, of about 0.5%,

add 2 kg. of hydrated lime and 7.3 kg. of caustic.

soda. At the end of about one hour a calcium pectate gel forms whichshould be broken up and neutralized by the addition of a suitablequantity of hydrochloric acid. During the preceding operation,considerable liquor will separate from the calcium pectate gel. Thisliquor should preferably be removed by straining through a suitablescreen. The calcium pectate should be further dewatered by pressing andmay or may not be subsequently dried. If dried, the dry calcium pectateshould be suspended in about liters of water to Which'has been added 12kg. of hydrochloric acid. The mixture should be allowed to stand for aperiod of time from about 1 to 24 hours, depending upon the size of thecalcium pectate particles. It is obvious that with finely groundparticles of calcium pectate the time necessary to complete the reactionwill be much shorter than with particles of a larger size. "The calciumchloride which is formedby the reaction of the hydrochloric acid and thecalcium pectate should be removed from the pectic acid by repeatedlywashing with water. The resulting pectic acid may be dried and ground.

Although alkali salts or alkaline earth salts of pectic acid may be usedas source material for the pectate radical, I have found it desirable touse pectic acid in place of the alkali or alkaline earth salts of pecticacid, since I thereby eliminate the step of removing the cation of thepectate, which,

if not removed, may decrease the effectiveness of the resultinginsecticide.

For the purpose of illustration, the invention will be described asapplied to the production of an insecticide containing pectic acid andnicotine alkaloid in the proportion of up to 55% nicotine based on theanhydrous weight of the pectic acid taken. It is to be understood thatthe description given hereinafter and relating to an insecticide of thistype is given for illustrative purposes only, since it represents asuitable product.

In one method for making the new composition of matter which I haveinvented, I prefer to proceed as follows:

Nicotine alkaloid and pectic acid from a suitable source, of which twohave been pointed out above, are reacted. This is accomplished by firstsuspending the pectic acid in a suitable quantity of water. This will,of course, be sufficient to make a fluid slurry. I then add the nicotinealkaloid, which is a liquid, in an amountup to about 55% based on themoisture-free weight, or socalled anhydrous weight, of the pectic acidused. Ordinarily, Iwill use about 50% of nicotine alkaloid, based on themoisture-free weight of pectic acid. The mixture is thoroughly andcarefully stirred. After the reaction has proceeded to completion, asevidenced by being comparatively free from the odor of nicotine, theresulting product is suitably dried.

As a specific example, I take 10 parts by weight of pectic acid(moisture-free) and suspend it by stirring in parts by weight of water.Then I add 5 parts by weight of nicotine alkaloid, and proceed as aboveoutlined.

The foregoing material will consist essentially of pure nicotinepectate, and will not contain any cation derived from a pectate, sincepectic acidis employed directly.

In another embodiment, I prepare a suitable material containing one formof my new oom-.

position of matter by precipitating calcium pectate in the form of a geland mixing therewith the stoichiometrical amount of nicotine oxalate.

Methods for forming calcium pectate gels are known. One known method isto dissolve sodium pectate in water and add calcium chloride in slightexcess. to precipitate as a gel. Thisgel may be washed with waterwithout destroying the gel form of the material. Sufficient of the gelis taken tobe equivalent to 10 parts by Weight of calcium pectate. Tothis is added 4.8 parts by weight of nicotine oxalate with thoroughstirring. Nicotine pectate and. calcium oxalate are formed.

In the foregoing procedure, I find it ordinarily desirable and moreeconomical not toremove-the calcium oxalate formed by the reactingingredients. The water may be removed from the above mixture in anysuitable manner, as by spray drying.

A similar procedure may be carried out using.

This causes the calcium pectate to my attention. A description of it isincluded" 7' here, as being a method that gives promise of beingthoroughly satisfactory commercially. It

is substantially as follows: I

The moisture content of a desired quantity of dried commercial pecticacid is adjusted to between 25 and 35% but preferably about 30% by U theaddition of water. After complete absorption of the added moisture,about 50% nicotine alkaloid (calculated on the anhydrous weight of thepectic acid taken) is thoroughly stirredinto the moist pectic acid. Thismixture is allowed to stand for about 24 hours, or until the reaction isX I complete as evidenced by only a slight odor of nicotine remaining.If desired, it may now be dried and packaged.

The product resulting from the above processes will be found to becomparatively free from the objectionable odors heretofore associatedwith nicotine and materials of vegetable origin.

If desired, coniine alkaloid, another Well known volatile poisonousalkaloid, may be substituted for nicotine alkaloid, or it maybedesirable to use some other volatile poisonous alkaloid. It is to benoted that synthetic nicotine or synthetic volatile poisonous alkaloidalmaterials may be substituted for the natural products.

Tests have been carried out on the toxicity of nicotine pectate ascompared with nicotine tannate. These tests have been conducted usingthe larvae of the silk moth as a test parasite. In a test using theinsecticides as a dust and comparing a nicotine tannate against thepectate, it was found that the pectate gave considerably better kills.In a like manner when these substances were used in the form of sprays,thepectate again proved superior to the nicotine tannate.

When using a pectate of nicotine as a dust, a satisfactory material maybe obtained by mixing 5% of the nicotine compound with 95% kaolin. If,on the other hand, one wishes to employ the material as a spray, asuitable water dispersuch as butyl diphenyl sodium sulfonate, sold 7commercially under the trade name, Aresket. This wetting agent may beused in dilutions of'l part of Aresket to 2000 parts of the spray. Insome cases it may be necessary to use lower dilutions to produce goodWetting and spreading on the foliage.

As stated hereinabove, it is to be understood that this invention is notlimited to the particular illustrations.

It is further tobe understood that variations in the proportions of myinsecticide may be necessary, when used as a spray or dust, depending onthe toxicity required to kill the particular parasite for which thespray or dust is being used;

Having thus described my invention in such clear, concise, and exactterms as to enable others skilled in the art to make, compound, and use,the same, I claim as my invention and desire to obtain by LettersPatent, the following:

I claim:

1. An insecticidal preparation containing the reaction product of pecticacid and a volatile poisonous alkaloid.

2. An insecticidal preparation containing the reaction product of pecticacid and nicotine alkaloid.

3. An insecticidal preparation containing the reaction product of pecticacid and coniine alkaloid.

4. As a new composition of matter a pectate of a volatile poisonousalkaloid.

5. As a new composition of matter a pectate of nicotine.

6. As a new composition of matter a pectate of coniine.

'7. A process for the preparation of an insecticidal material comprisingreacting pectic acid with a volatile poisonous alkaloid.

8. A process for the preparation of an insecticidal material comprisingreacting pectic acid with'nicotine alkaloid.

9. A process for the preparation of an insecticidal material comprisingreacting pectic acid with coniine alkaloid.

10. A process for the preparation of an insecticidal material comprisingsuspending pectic acid in a suflicient excess of water to form a fluidslurry, and reacting a volatile poisonous alkaloid with the pectic acidby adding the alkaloid to the slurry and stirring the same.

WIIILARD E. 'BAIER.

